The Sticky Particle Model - Ising meets SEP

Condensed Matter lunchtime seminar

The Sticky Particle Model - Ising meets SEP

Event details

I will describe a simple statistical mechanics model for sticky particles moving in 1D.   It is the simplest model for diffusive flow driven from the boundary rather than by asymmetry within the system.

The model involves particles hopping between sites.  Each site can contain at most one particle, the hopping rate depends on whether or not the particle has a neighbouring particle.  This rate introduces the only parameter in the model, the stickiness.    Flow is controlled by setting boundary densities.

We have analysed the model using Mean Field Theory, Transition Rate Matrices and Monte Carlo simulations.  I will discuss each of these techniques.

The model exhibits extraordinarily rich behaviour which we do not fully understand.  Notably, there is a phase change from a free-flowing to a "stuck" state for sufficiently high stickiness.   With zero stickiness, the model is just the simple exclusion process with normal diffusive flow.  With attractive particles, the density in the bulk system becomes higher than at either boundary, unsurprisingly.  With repulsive particles, the density in the bulk system also becomes higher than at either boundary: we find this counterintuitive.

All this work was done by Joshua Hellier in his PhD.  We find it extraordinary that this simple model does not seem to have been studied before.

About Condensed Matter lunchtime seminars

This is a weekly series of informal talks given primarily by members of the soft condensed matter and statistical mechanics groups, but is also open to members of other groups and external visitors. The aim of the series is to promote discussion and learning of various topics at a level suitable to the broad background of the group. Everyone is welcome to attend..

Find out more about Condensed Matter lunchtime seminars.